The present invention is directed to an attachment nut formed of a base member and an elastic retaining insert connected to the base member. The base member has a means for engaging a force applying member and a first dimension extending generally perpendicularly of a second dimension.
An attachment nut of the above-described type is disclosed in U.S. Pat. No. 3,493,024 and serves for securing components to profiled rails where the rail is essentially C-shaped in cross-section. Two legs of the profiled rail, extending parallel to one another, extend into the interior of the rail. The base member is located within the profiled rail and in the preassembled state is axially displaceable within the rail. A retaining insert connected to the base member abuts an outside surface of the profiled rail in the region of a slot-like opening bounded by the two legs.
The base member has an out of round outside shape, whereby the smallest dimension of the outside shape is smaller than the width of the slot-like opening measured perpendicularly to the longitudinal extent of the profiled rail. The base member has a central throughbore with means in the form of an internal thread for engaging a force applying member and two toothed sections or regions extending parallel to one another which cooperate with the free ends of the legs when the attachment nut is inserted into the profiled rail. After this insertion, the basic member can be turned through 90.degree. into its preassembly position.
The retaining insert has a central first region in axially fixed connection with the base member and an elastic collar-like second region abutting the outside surface of the profiled rail in the region of the slot-like opening. The retaining insert has a central passage of essentially the same size as the diameter of the throughbore in the base member or of a shank of a clamping screw which extends through the central passage of the retaining insert into the central throughbore of the base member for securing a component to the profiled rail.
This known attachment nut has the disadvantage that it is difficult to manually turn the attachment nut for its preassembly in the profiled rail, since the attachment nut is difficult to grip. There is another disadvantage in that the attachment nut tends to turn when a clamping screw is tightened in the through bore, so that the nut detaches itself from the preassembled position whereby the base member no longer rests against the free ends of the legs of the profiled rail.